1. Field of the Invention
This invention relates to a washer apparatus designed to apply a specified varying load along different radians of a washer for a given deflection, and more specifically to a washer adapted to seal with a non-parallel surface.
2. Prior Art
Although a plurality of seals and washers are known in the art which are adapted to seal planar, parallel members, there is not known to be any effort made to seal a curved member to a planar member. Specifically, when a curved surface such as a dome is equipped with a polar boss, or a seal along an opening of the curved surface, additional force is necessary on an outer portion of the seal than on the inner portion of the seal to achieve equal O-ring compression. A need exists to provide a washer or seal design that can provide relatively equal force along a curved surface.
Consequently, it is a primary object of the present invention to apply a specified varying load along a radian for each cross section of a circumference of a washer.
It is a further object of the present invention to provide a washer to deploy a seal wherein the seal transfers a uniform load from one surface to a linearly varying load on another surface.
Another object of the present invention is to provide a washer adapted to provide relatively constant force along an external surface when one surface of the washer contacts a curved surface.
Accordingly, the present invention provides a variable pressure washer having two interlocking rings, preferable channel rings defining a channel there between. A captive set of fasteners may be utilized to prevent the channel rings from coming apart. In the preferred embodiment, a plunger moving within a plunger housing acts as the captive fastener set and determines the range of movement of the channel rings relative to one another. Within the channel between the rings are at least two compressible springs which exhibit different characteristics, specifically, differing stiffness or spring modulus values. The springs are preferably devices such as metallic springs, thermoplastic rings, etc. . . . Retaining members, such as cups, may be utilized to locate the springs in a desired position within the rings.